Electrical energy generator device with micro-fan array

ABSTRACT

An electrical energy generator device comprising an array of micro-fans each associated to a respective dynamo-electric generator by means of a respective connecting shaft, further comprises, for at least some of the micro-fans ( 3 ), a lug element ( 6 ) associated to the respective connecting shaft ( 4 ) which mechanically co-operates at each revolution with a piezoelectric element ( 7 ), for the production of additional electrical energy. In addition or instead of the aforesaid arrangement, it is possible to provide plates ( 10 ) made of piezoelectric material which vibrate in the flow of air that invests them, thereby producing electrical energy.

The present invention relates to an electrical energy generator device,comprising an array of micro-fans, each associated to a respectivedynamo-electric generator by means of a connecting shaft.

A device of the kind described above has been the subject of theprevious patent application No. T02001A000386 of Apr. 20, 2001 by thesame Applicant. The previously proposed device was applicable both to amotor vehicle, where the relative wind generated by the motion of themotor vehicle can be exploited to actuate the rotation of the micro-fanswith the consequent generation of electrical energy, and in general as astationary generator device actuated by wind energy, for instance toenergise the lighting of road signs or the like.

Studies and experiments conducted by the Applicant have shown that thepreviously proposed device has the advantage of allowing to generateelectrical energy even at low or very low velocities of rotation of themicro-fans. On the other hand, in the case of high velocities ofrotation, the generation of electrical energy can be limited to acertain extent by the fact that dynamo-electrical generators undergo asaturation phenomenon above a threshold velocity.

The object of the present invention is further to enhance the previouslyproposed device, overcoming the aforementioned drawback.

In view of achieving said object, the invention relates to a device ofthe type described above, characterised in that at least some of themicro-fans are connected to the respective dynamo-electric generatordevices by means of shafts, each of which bears at least a lug elementable to co-operate mechanically at each revolution with a piezoelectricelement which produces additional electrical energy.

The arrangement of the piezoelectric elements allows to produceelectrical energy in particularly efficient fashion at the highvelocities of rotation of the micro-fans.

According to an additional preferred characteristic of the invention,the aforesaid piezoelectric element is constituted indifferently by apiezoelectric polymer or by a piezoelectric ceramic.

Further features and advantages of the invention shall become morereadily apparent from the description that follows with reference to theaccompanying drawings, provided purely by way of non limiting example inthe accompanying drawings, in which:

FIG. 1 is a perspective view of a generator device comprising an arrayof micro-fans,

FIG. 2 is a schematic sectioned view of a device according to theinvention, showing the details of the connection between a micro-fan andthe related dynamo-electric current generator and of the lug elementassociated with the shaft and co-operating with the piezoelectricelement.

In FIG. 1, the reference number 1 globally designates a generator devicecomprising a support structure in which are pivotally mounted aplurality of micro-fans 3, arranged in a matrix. With reference to FIG.2, each micro-fan is mechanically connected by a shaft 4 to adynamo-electric generator 5 for the production of electrical energy.According to the invention, on the shaft 4 is also mounted a lug element6 which, rotating with the shaft 4, comes in contact at each revolutionwith a piezoelectric converter 7 which is thereby mechanically stressedand consequently determines the production of additional electricalenergy.

As was previously mentioned, the array arrangement of the micro-fansallows to generate electrical energy in particularly efficient fashionby means of the generators 5 at low velocities of rotation of themicro-fans, whilst said production is, in itself, relatively limited athigh velocities, due to the saturation of the generators 5. Thepiezoelectric polymers 7 enable to overcome said limitation, becausethey enable to produce electrical energy in particularly efficientfashion at high velocities of rotation.

FIG. 3 shows an additional solution which is also comprised in thepresent invention in which no micro-fans but solely a plurality ofplates of piezoelectric material 10 which are positioned in thedirection of a flow of air F in a conveying conduit 11. The flow of airF causes a vibration of the piezoelectric plates 10 which consequentlycauses the production of electrical energy.

Naturally, it would be possible to provide a generator device in whichthe piezoelectric plates 10 are used in parallel with the utilisation ofthe micro-fans described above.

Naturally, without altering the principle of the invention, theconstruction details and the embodiments may vary widely from what isdescribed and illustrated purely by way of example herein, withoutthereby departing from the scope of the present invention.

1. An electrical energy generator device, comprising an array ofmicro-fans (3) each associated to a dynamo-electric generator (5) bymeans of a respective connecting shaft (4), characterised in that for atleast some of the micro-fans (3), the connecting shaft (4) is providedwith a lug element (6) which mechanically co-operates at each revolutionwith a piezoelectric element, for the production of additionalelectrical energy.
 2. A generator device as claimed in claim 1,characterised in that the piezoelectric element is a piezoelectricpolymer or a piezoelectric ceramic.
 3. An electrical energy generatordevice, characterised in that it comprises one or more plates (10) ofpiezoelectric material positioned in the direction of a flow of airwithin a conduit (11) for conveying air, in such a way that said platesare forced to vibrate by the flow of air and consequently produceelectrical energy.